Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It adds one behavioral trait: 'Page content is not stored,' which is useful privacy context. However, it omits whether network requests are made, error behavior, and what happens with the other parameters. For a tool that likely performs network I/O, this is insufficient.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, efficient, and front-loads the core function. The extra note about not storing content is relevant and concise. No wasted words, though it could benefit from a sentence about parameter use.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given four parameters, no output schema, no annotations, and a crowded sibling set, the description is under-specified. It doesn't explain how the parameters interact, when to invoke it, or what the response looks like. An agent would struggle to call this correctly beyond the obvious URL case.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema documents each parameter. The description adds no parameter-specific meaning beyond the schema; it doesn't clarify how url, host, json, and zone relate to the stated purpose. Baseline 3 applies because the schema carries the load, but the description adds little extra value.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a clear primary function: 'Return host, scheme, and HTTP status for a URL.' It identifies a specific verb and resource. However, it doesn't differentiate from siblings like normalize-url or status-catalog, and the presence of unrelated parameters (host, json, zone) muddies the intended scope, making the purpose less crisp.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus alternatives. It neither mentions sibling tools nor provides conditions for selection. The description implies it's for citing a URL, but does not exclude normalize-url or status-catalog, leaving an agent without decision support.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.